That means the industry could still meet analysts' U.S. sales expectations of 17.25 million vehicles for March on an annualized basis. Analysts polled by Reuters expected an increase in sales of about 7 percent from a year earlier.

Monthly auto sales are an early indicator of U.S. consumer behavior.

Normally the largest U.S. automaker, GM said its U.S. sales rose 0.9 percent to 252,128 vehicles, about 2,600 fewer than crosstown rival Ford. Analysts polled by Reuters had on average expected GM to sell 260,500.

Sales to consumers rose 6 percent, GM said, as it pulled back on its sales to rental agencies, a business that cuts into its profit.

The company plans to cut sales to U.S. rental car fleets by 80,000 to 90,000 vehicles this year without surrendering significant market share, GM told Reuters earlier this week.

GM and Ford shares were down nearly 3 percent on Friday morning, while Fiat Chrysler fell almost 5 percent. The broader Standard & Poor's 500 index .SPX was down just 0.1 percent.

Ford said its U.S. auto sales rose 8 percent in March as the company benefited from strong demand for its pickup trucks and SUVs.

The company's average selling price of its vehicles rose $1,600 in March, said U.S. sales chief Mark LaNeve.

Nissan reported a 13 percent gain on the strength of its mainstay sedans.

Low gasoline prices, relatively low interest rates and stronger employment have helped boost U.S. auto sales for several years. Demand is also heightened because vehicles have been on road for an average of more than 11 years.

The strengthening U.S. job market is bullish for auto sales as it generally gives consumers confidence to take out a car loan, analysts have said.

U.S. non-farm payrolls rose in March by 215,000, slightly topping forecasts, and wages rebounded, government figures showed on Friday.

But U.S. consumer sentiment reported by the University of Michigan on Friday fell in March to its lowest level since October.